1. Field of the Invention
This invention relates to a solid-state image pickup device and to a method for manufacturing the same. In particular, this invention relates to a solid-state image pickup device wherein a color filter is utilized also as a lens member and to a method of manufacturing the same.
2. Description of the Related Art
In recent years, digital cameras and video cameras utilizing a solid-state image pickup element such as a charge coupled device (CCD) and complementary metal oxide semiconductor (C-MOS) device have been increasingly popularized and, at the same time, the techniques to further miniaturize the solid-state image pickup element by making use of a chip-size package (CSP) system have been developed. The solid-state image pickup element of such a small size is suitable for building into electronic equipment such as mobile telephones where miniaturization, lightness and slimness are desired.
Since the light-receiving face of each of the pixels of solid-state image pickup element is constituted by a rugged surface, it is generally practiced to deposit a transparent flattening layer on the surface of the solid-state image pickup element, thereby flattening the surface of the solid-state image pickup element. More specifically, as shown in FIG. 1, a first flattening layer 13 is deposited at first on the surface of a solid-state image pickup element 11 in which a plurality of photoelectric conversion elements 12 such as CCD are two-dimensionally arranged. Then, a color filter 14 comprising color layers of plural kinds of colors is formed on the first flattening layer 13 and a second flattening layer 15 is formed on the surface of the color filter 14. Furthermore, convex lenses 16 for condensing light are formed on the second flattening layer 14 (see for example, JP-A 2006-41467).
In the manufacture of the solid-state image pickup element constructed in this manner, the first flattening layer 13, color filter 14, second flattening layer 15 and convex lenses 16 are required to be successively formed, raising many problems such as the requirement of a large number of steps, deterioration of yield and increase of manufacturing costs.
There is another problem that since a large number of intervening layers such as the first flattening layer 13, color filter 14 and second flattening layer 15 are interposed between the light-receiving face and convex lens 16 and hence the light-receiving face is fairly spaced away from the convex lens 16, the light-collecting efficiency is degraded and attenuation of light is more likely to occur in the path by which the light reaches the photoelectric conversion element 12.